diff --git a/include/restclient-cpp/connection.h b/include/restclient-cpp/connection.h
index 5f82c7c6..12984fe7 100644
--- a/include/restclient-cpp/connection.h
+++ b/include/restclient-cpp/connection.h
@@ -13,6 +13,7 @@
 #include <string>
 #include <map>
 #include <cstdlib>
+#include <cstdint>
 
 #include "restclient-cpp/restclient.h"
 #include "restclient-cpp/version.h"